Harris tabor



-(No Mqdel.)

H TABOR ART OF MAKING METAL FOUNDER3 PATTERNS.

Patented Aug. 6, 1889.

Inventor Witnesses Attorney WWA. G4

N. FEYERS. mwuuw mr. Washinglan. o c,

V UNITED STATES.

HARRIS TABOR, OF NEW YORK, NY,

PATENT ()FFICE.

ASSIGNOR TO THE TABOR MANUFAC- TURING COMPANY, OF SAME PLACE.

ART OF MAKING METAL-FOUNDERS PATTERNS.

. SPECIFICATION forming part of Letters Patent No. 408,677, dated August6, 1889. v Application filed September 22, 1888.. Serial No. 286,108.(No model.)

To all whmn it may 0077106777 Be it known that I, HARRIS TABOR, of NewYork, New York county, New York, have invented certain new and usefulImprovements inthe Art of Making Metal-Founders Patterns, of which thefollowing is a specification.

This invention pertains to improvements in the art of making patternsfor the use to of the metal-founder. In ordinary procedure a pattern ofthe desired form is made in wood or other material, which can beproperly worked to the shape desired, and the product represents thepattern used by the IS metal-founder in producing the molds for metalcastings of the form of the pattern. Often these original patterns aretoo fragile for continued use, and often they are wanted in multiple. Insuch case it is usual to smooth up castings made from the originalpatterns,

and these castings become in turn the patterns for actual use. The metalcastings thus used for patterns have the disadvantage of being smallerthan the original wooden patterns by reason of the shrinkage of themetal, and, furthermore, the proper dressing of the metal surface to fitthem for use as patterns is very laborious .and expensive. Especially isthis the case in stove-patterns,if the labor 0 be carried far enough tosecure in the metal patterns that peculiar sharpness of detail presentin the original Wooden pattern,but lost in the process of casting. Instove-work the patterns as ordinarily made involve also 3 5 theproduction, generally by carving process,

of the follow-board. The use .of these patterns, often with the mostclosely-fitted fol- I low-board, requires extraordinary skill onthe fpart of the molder in forming his mold-joints 0 so as to produce finework. In all patterns of wood or of metal, and regardless of how theirsurfaces may have been treated for smoothness, there is often found.great difficulty in getting the pattern to leave the sand nicely in theabsence often of such an amount of draft as might not for other reasonsbe desirable. In the later developments of molding by molding-machinesor molding-presses a reproduction of the patterns in a modified 'formsuited for application to the machines is generally called for, and theexpense of this duplication of patterns, already satisfactory forhand-molding, has constituted a serious obstacle to th eintroduction ofmoldingmachines.

By means of'my improvement-s I am able to duplicate the original woodpatterns or metal patterns at comparatively trifling cost, and toproduce patterns without additional costhaving the property of drawingwith peculiar freedom and cleanness from the sand, and, ifdesired,-specially adapted for use in connection with molding-machines,and, if desired, avoiding the necessity for any separate follow-boards,and also, if desired, patterns capable of serving in the moldingmachinefor both half-flasks, which make up the complete mold.

My improvements in the art willbe readily understood from the'followingdescription, taken in connection with the accompanying drawings, inwhich- Figure 1 is a perspective view of an example casting to beproduced, and also the usual form of pattern corresponding preciselywith the casting; Fig. 2, a perspective view of the two parts of themold or flask in whichthis pattern has been molded; Fig. 3, aperspective view of one of these half-molds with a pattern-margin placedthereon; Fig. 4, a side elevation of a pattern-margin for the other oneof the half-flasks5 Fig. 5, a perspective view, on a somewhat reduced.scale, of the two parts of the complete pattern with their man ginsshown as mounted upon a bed or platen for a molding-machine; and Fig. 6,a vertical longitudinal section, upon a somewhat reduced scale, of thehalf-flask and pattern-margin shown in Fig. 3, illustrated inconjunction with a stripper-plate.

In the drawings, A indicates an ordinary wood or metal pattern havingthe form and dimension of the casting to be produced from it, except ofcourse as to the usualallowance for shrinkage, and thus may therefore betaken as indicating also the casting to be produced, the delineationanswering for both the pattern and the casting; B, one of thehalf-flaskssay the drag; 0, female dowel elements attached, as usual, tothe drag; D, the other half-flask-the cope; I), male dowel elementsattached, as usual, to the cope and adapted to properly engage the dowelelements of the drag; F, that portion of the sand standing in the dragand left by the interior of the pattern when the pattern is withdrawn;G, the flat joint-surface of the drag-mold around the standing pattern;II, the moldcavity in the cope formed by the exterior of the patternwhen withdrawn; J, the joint-surface of the cope-sand around thiscavity; K, a pattern-margin in the form of aframe, preferably of metalcorresponding with the cope and forming practically a shallowcontinuation of the depth of the same; L, female dowel elements on thispattern-margin adapted to engage the dowel-pins of the cope; M, flangesupon the pattern-margin, adapted to serve in securing the same to aboard or plate, as the bed or platen of a molding-machine; N, anothersimilar patternqnargin for the drag; 0, male dowel elements on thispattern-margin adapted to engage the dowel elements of the drag; P, thebed or platen of the molding-machine; Q, that portion of my improvedpattern corresponding to the exterior of the pattern A and fitting themold-cavity H of the cope; R, the flat joint-surface of this copeportion of the pattern fitting the joint-surface J of the cope-mold; S,that portion of myimproved pattern corresponding with the interior ofthe pattern A and fitting the standingsand F of the drag; T, the flatjoint-surface of this drag portion of the improved pattern, and U theusual stripper-plate.

In executing my improvement in the art the process is as follows: Thepattern A, be it wood or metal, is molded up as usual and the flaskopened and the pattern withdrawn, leaving the mold as it appears in Fig.2. It is desirable that the mold-surface be as smooth and true aspossible. If the character of the pattern will permit it, the mold is tobe dusted, as usual, with facing and the pattern returned. If thecharacter of the work will not permit the return of the pattern, then informing the mold the mold-surface directlyin contact with the patternmaybe formed of special fine sand mixed with facing or of suitablefacing alone. The cope is then laid upon its back, as in Fig. 3, and thepattern-margin K is placed upon it, the dowel elements intermemberingand the pattern-margin fitting neatly down upon the edges of the flask.It is highly desirable, where my improvements are introducedsystematically into a foundry, to have an interchangeable system offlasks, so that any cope of a given size will properly dowel with anydrag of corresponding size, and the pattern-margins will therefore ofcourse properly intermembcr with these flask parts. The pattern-margin Kis to be preferably of castiron, with accurately-fitted dowel elements,and the interior surface of the pattern-margin should be roughened orotherwise provided to hold the pattern material into firm union with thepattern-margin. The parts being properly arranged, as in Fig. 3, thematerial of which the pattern is to be made is poured into the cope-moldand pattern-frame until even' with the top of the latter, when it may bestruck off level. Any suitable material may be employed for the pattern.It should be capable of flowing freely and filling the mold accurately,and of forming, when solid, a properly smooth pattern-surface, and itshould be free from objectionable shrinkage. I prefer Portland cement asthe material to be employed. Mix the cement so it will flow freely, andhandle it rapidly and pour quickly. \Vhen this material is used, Irecommend graphite as afaeing material. Let the parts remain untilproperly set and hard say twenty-four hours or more. The patternmarginmay then be lifted from the cope, and the cement pattern will be foundjoined up integral with it. The cope-mold will be no longer required.Zrush the sand from the pattern-surface and let the pattern harden, say,for some days. The pattern may be further smoothed, but this will seldombe necessary.

The pattern part thus produced will obvi ously exactly fit themold-cavity II and the joint surface J of the drag. If this pattern partbe secured by the margin-flanges to the bed or platen of amolding-press, itis obvious that when the cope is properly engaged withthe pattern-margin and sand compacted in thecope and the patternwithdrawn a copemold will hzwe been produced which is the identicalcounterpart of the cope in which the pattern was made and it is furtherobvious that this pattern part may then be used to produce any number ofidentical copemolds, and it is further obvious that by the processindicated more of these identical pattern parts may be produced, so thatmore extensive molding operations upon one character of castings may becarried on.

A pattern part for the drag-mold is produced in precisely the samemanner as has been indicated for the copepart. This gives two patternparts, one of which may be used in forming copes and the other of whichmay be used in forming drags, and these copes and drags will properlyintermember and produce perfect and complete mold-cavities, each patternpart being used separately in the molding process; but I carry myimprovements farther and arrange so that each effective impulse of themolding-machine shall produce a complete moldthat is to say, the copeand the drag. I secure the two pattern parts with their backs againstthe bed or platen of a molding-machine, as indicated in Fig. 5. The bedor platen of the machine therefore presents pattern features adapted foroperation upon the drag and cope at once, whereby each effective impulseof the machine produces a cope and a drag, which, when closed, form thecomplete mold.

IIO

Gates andsprue-holes will be provided, of course, in the mold, as usual,and in the usual process, or they may be provided for in the form of thepattern, or by the means usually employed in machine-molding. Fig.therefore represents a complete pattern fitted for peculiarly-accuratemolding and avoiding the necessity. for expensive follow-boards andadapted for peculiarly-rapid work in the molding-machine, and thepatterns are of a very inexpensive character, the entire cost ofproducing these complete patterns by the improved process being far lessthan the cost of reproduction byan y of the earlier processes and inmany cases less than the cost of follow-boards alone, and less than thecost of of Wood in the upper surface of the material before it hardens,these blocks forming wooden spots in the back of the pattern parts,into which the draw tools maybe readily driven I without injury to thepattern part.

My improvements have in view principally the employment ofmolding-machines in which the pattern is withdrawn from the sand by theoperation of the machine, as is common in machine-molding. Somecharacters of patterns call for the employment of stripper-plates, andin such cases these plates are fitted and used in the usual manner, thepattern part being of course correspondingly deepened. Thus, in Fig. 6,the pattern-margin K, instead of resting directly upon the edges of thecope, has the stripper-plate U interposed. The projection of the patternpart from the joint part of the pattern will therefore have an increaseddepth due to the thickness of the stripper-plate. The stripperplatehaving the precise contour of the moldcavity, it is obvious that thepattern material poured in to the mold-cavity and stripperplate fits thestripper-plate with absolute accuracy.

There are pattern producing processes which yield the fundamentalpattern; others which produce a match-board with the fundamental patternattached thereto, and therefore not pattern-duplicatin g processes;others which producea parting-plate with a patternface on each side ofit; others which involve the making of intermediate waste-molds ofplaster or the like, thus involving a moldshrinkage as well as apattern-shrinkage. I disclaim such processes. My process utilizes anordinary pattern and an ordinary sand mold made thereon, and producesany desired number of working-patterns direct from such sand mold. Myprocess yields working-patterns, in any desired number, in truecorrespondence to the fundamental pattern, unmodified by mold-shrinkage.

I claim as my invention- 1. That improvement in the art of makingmetal-founders patterns which consists in, first, producing a patternhaving the form of the casting desired; second, producing a doweledtwo-part sand mold therefrom; third, laying the two mold parts upontheir backs; fourth, fitting dowel elements to the dowel elements ofsaid separate mold parts, and, fifth, pouring a suitable pattern-formingmaterial into said separate mold parts and into connection with saidfitted dowel elements, whereby are produced two pattern parts eachfitting the mold portion and dowel elements of its respective mold part.

2. That improvement in the art of making metal-founders patterns whichconsists in, first, producing a pattern having the form of the castingdesired; second, producing a dow- I eled two-part sand mold therefrom;third, laying the two mold parts upon their backs; fourth, fitting thedowel elements to the dowel elements of said separate mold parts; fifth,pouring a suitable pattern-forming material into said separate moldparts and into connection with said fitted dowel elements, and, sixth,securing the two pattern parts thus produced side by side with theirbacks against a bed or platen, whereby is produced a pattern adapted, byone impression in one direction, to produce two half-molds which willjoin and form a perfect mold.

3. That improvement in the art of making metal-founders patterns whichconsists in, first, producing a pattern having the form of the castingdesired; second, producing a doweled two part sand mold therefrom;third, laying the two mold parts upon their backs; fourth, laying aproper stripping-plate upon the mold-faces in dowel engagement with thedowel elements of the mold parts; fifth, fitting dowel elements to thedowel elements of said separate mold parts, and, sixth, pouring asuitable pattern-forming material into said separate mold parts and saidstripping-plates and into connection with said fitted dowelelements,wherebyareproduced two pattern parts each fitting the moldportion and-dowel elements of its respective mold part andstripper-plate.

HARRIS TABOR.

Witnesses:

C. E. RUGGLES, E. O. POND.

